1. Field of the Invention
This invention relates to a chewable object for animals which contains one or more enzymes and substrates for the purpose of generating antimicrobial compounds upon contact with an animal's saliva. More specifically, chewable and consumable compositions are herein described which, upon being chewed, produce hydrogen peroxide or other antimicrobial agents.
2. Art Background
A number of naturally occurring antimicrobial systems rely upon the ability of certain oxidizing agents to disrupt metabolic processes of bacteria, fungi and viruses. Compounds such as hypothiocyanite (OSCN-/HOSCN), hypochlorite (OCI-, HOCl), and hypoiodite (OI-, HOI) are known to inhibit glycolysis, penetrate prokaryotic cell walls, and generally disrupt a wide variety of processes crucial to the survival of lower organisms. These oxidizing agents are the result of the detoxification of hydrogen peroxide by mammalian peroxidase systems, such as those found in saliva, cervical fluid, lacrimal fluid, and leukocytes.
The antimicrobial effectiveness of the aforementioned oxidizing agents is well established in the literature and is known to occur at concentrations of about 100 micromoles per liter. The limiting factor in all of the mammalian antimicrobial peroxidase systems is the availability of hydrogen peroxide.
The numerous prior art attempts to activate or supplement natural antimicrobial peroxidase systems are generally limited to the oral care field. U.S. Pat. No. 4,150,113 and U.S. Pat. No. 4,178,362 (Hoogendorn, et al) describe dentifrices containing glucose oxidase in order to react with plaque and salivary glucose to produce low levels of hydrogen peroxide.
U.S. Pat. Nos. 4,269,822, 4,564,519 and 4,578,265 (Pellico, et al.) further describe dentifrice compositions containing an oxidoreductase enzyme, together with its specific substrate, for the purpose of producing hydrogen peroxide or other antimicrobial oxidizing compounds, such as hypothiocyanite ion. In each of these prior art formulations, the oxidoreductase enzymes and substrates are in aqueous solution and homogeneously distributed throughout the entire mixture.
U.S. Pat. No. 4,564,519 describes a chewable dentifrice, such as a chewing gum or lozenge, which contains a dual enzyme system for producing hypothiocyanite ions upon being chewed or otherwise activated by the moisture in saliva. All of the above compositions teach a manufacturing and compounding process whereby the enzymes, and, optionally, the substrates are distributed homogeneously throughout the entire composition.
In addition to U.S. Pat. No. 4,564,519 above, other solid or chewable compositions capable of producing hydrogen peroxide or other oxidizing agents upon activation with moisture are taught in U.S. Pat. Nos. 4,320,116, 4,726,948, and 4,929,466. These compositions are foodstuffs intended for consumption by livestock in order to limit the growth of harmful bacterial within the animal's gastrointestinal tract. The authors also teach a manufacturing and compounding process whereby the enzymes and substrates are distributed homogeneously throughout the composition.
It is well known to those skilled in the art that enzymes are reactive with their corresponding substrates when present together in aqueous solution. It is also well known by those skilled in the art that most enzymes are thermosensitive and frequently undergo a gradual, but irreversible inhibition when exposed to temperatures higher than 5 or 10 degrees Celsius for extended periods of time.
Since domesticated animals, such as dogs, are unable to practice any type of oral hygiene, they are more at risk for caries, gingivitis and periodontal disease than their human counterparts. It would thus be advantageous to provide a chewable and consumable object for animals which contains or can produce agents effective in reducing or eliminating oral pathogens associated with such diseases.